This invention relates to a method of treating human skin and more particularly is directed to the alleviation of acne by applying to the infected area a mixture of an antimicrobial agent and a volatile cyclic silicone. The mixture is delivered to the skin by entrapping the mixture within particles of a hydrophobic macroporous highly cross-linked polymer.
The concept of producing spheres and beads of a macroporous polymer is old in the art as is the use of such macroporous structures for the entrapment and subsequent delivery of certain active ingredients. One example of this concept may be found in U.S. Pat. No. 4,690,825 issued Sep. 1, 1987 in which a suspension polymerization process is employed to produce beads from a monomer system including styrene and divinylbenzene. Mineral oil is entrapped "in situ" and the beads are stated to possess utility in various cosmetic applications. In U.S. Pat. No. 4,719,040 issued Jan. 12, 1988 a macroporous polymer laden with perfume is incorporated into an air freshener gel. U.S. Pat. No. Re. 33,429 issued Nov. 6, 1990; European Patent 61,701 granted Jul. 16, 1986; and Canadian Patent 1,168,157 issued May 29, 1984; each relate to "in situ" entrapped moisturizers carried within macroporous beads. Various cosmetic and toiletry applications of these products are also disclosed.
A macroporous polymer entrapping an emollient is taught in U.S. Pat. No. 4,764,362 issued Aug. 16, 1988 and in U.S. Pat. No. 4,813,976 issued Mar. 21, 1989, in which the polymer is incorporated into a nail conditioning emery board. During filing of the nails, the emollient is released in order to condition and lubricate the nails. A similar concept is taught in U.S. Pat. No. 4,776,358 issued Oct. 11, 1988 in which a dental floss includes flavor oils entrapped in certain "microsponges". Suspension polymerized macroporous polymer beads are taught in U.S. Pat. No. 4,806,360 issued Feb. 21, 1989 and in U.S. Pat. No. 4,855,144 issued Aug. 8, 1989, wherein melanin pigment is incorporated into the macroporous structure and applied to the skin to function as a sunscreen. Similar bead structures are also taught in European application 306 236 published Mar. 3, 1989 and in Patent Cooperation Treaty International application WO 88/01164 published Feb. 25, 1988. Beads carrying a cationic charge in order to improve the adhesion to hair and skin are described in European application 369 741 published May 23, 1990.
A reticulated polyurethane foam is disclosed in U.S. Pat. No. 4,828,542 issued May 9, 1989 having macroporous polymer particles bonded to the foam. The particles entrap a liquid soap and the foam functions as a cleaning pad. In U.S. Pat. No. 4,855,127 issued Aug. 8, 1989 and U.S. Pat. No. 4,880,617 issued Nov. 14, 1989, hydrophobic polymeric porous beads are used as a free-flowing solid carrier for various pheromones, pesticides, fragrances and chemicals entrapped therein. Hydrophilic beads are formed in U.S. Pat. No. 4,870,145 issued Sep. 26, 1989 and upon removal of the solvent used to form voids, the beads possess various utilities such as incorporation into contact lens cleaners, facial scrubs and tile cleaners. In U.S. Pat. No. 4,873,091 issued Oct. 10, 1989 resilient microbeads are formed by suspension polymerizing curable elastomers such as isoprene rubbers to produce porous rubber beads. The porous rubber beads are employed in topical applications. In the Patent Cooperation Treaty International application WO89/10132 published Nov. 2, 1989 porous particles are disclosed as an ingredient in personal care emulsions. A pet litter is described in U.S. Pat. No. 4,881,490 issued Nov. 21, 1989 and U.S. Pat. No. 4,883,021 issued Nov. 28, 1989, wherein a macromolecular polymer entrapping a fragrance is incorporated into an animal litter to slowly release fragrance for combating odors.
In U.S. Pat. No. 4,898,913 issued Feb. 6, 1990 macroporous hydrophobic powder materials are rendered hydrophilic by treatment of the surface of the powder. In one embodiment of the '913 patent, the surface is saponified whereas in another embodiment an acrylate monomer is polymerized on the surface. A wet wipe useful in personal care applications is disclosed in U.S. Pat. No. 4,904,524 issued Feb. 27, 1990 wherein macroporous polymeric beads containing a silicone skin conditioner are incorporated into the surface of a paper sheet. Polymeric microparticles loaded with a fungicide are taught in U.S. Pat. No. 4,923,894 issued May 8, 1990. In U.S. Pat. No. 4,933,372 issued Jun. 12, 1990 there is described rigid resin particles formed by polymerizing monounsaturated and polyunsaturated monomers within the pores of inorganic template particles such as silica gel, silica, alumina, zirconia and metal oxides. The template particles are dissolved leaving porous adsorptive particles which mirror the template particles in size, surface area and porosity. Macroporous particles capable of adsorbing hydrophilic as well as lipophilic fluids are taught in U.S. Pat. No. 4,948,818 issued Aug. 14, 1990. Similar materials can be provided in bulk form as polymerized plugs containing entrapped pheromones in accordance with apparatus described in U.S. Pat. No. 4,958,999 issued Sep. 25, 1990. A fragrance dispenser device in the shape of an hourglass containing reticulate particulates entrapping an aroma chemical is depicted in U.S. Pat. No. 4,961,532 issued Oct. 9, 1990. In U.S. Pat. No. 4,962,133 issued Oct. 9, 1990 a process for producing macroporous particulates is described including the the inclusion of an azeotrope to enable an inorganic initiator to be employed. The '133 patent also contains a review of the prior art, a comprehensive list of the uses of such materials, and functional and active ingredients which may be entrapped therein. Similar materials produced by polymerizing only polyunsaturated monomers are set forth in U.S. Pat. No. 4,962,170 issued Oct. 9, 1990.
In accordance with the present invention however, a new and novel combination including such materials as a carrier has been discovered wherein provision is made for excess skin oil adsorption into the materials in addition to contact of the skin with entrapped acne treatment ingredients. The macroporous particles have been found to function as a skin oil absorbent when delivered in combination with a volatile cyclic silicone and an antimicrobial agent.